[wasm] Initial signal handler

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index bac61301c6a465bab8257b91e2c1dbbebd84471f..10e845a49940457760689e57c5db370c1d611a84 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -1202,6 +1202,10 @@ Object* Isolate::UnwindAndFindHandler() {
   for (StackFrameIterator iter(this); !iter.done(); iter.Advance()) {
     StackFrame* frame = iter.frame();
 
+    if (frame->is_wasm() && trap_handler::IsThreadInWasm()) {
+      trap_handler::ClearThreadInWasm();
+    }
+
     // For JSEntryStub frames we always have a handler.
     if (frame->is_entry() || frame->is_entry_construct()) {
       StackHandler* handler = frame->top_handler();
@@ -1233,6 +1237,13 @@ Object* Isolate::UnwindAndFindHandler() {
 
           handler_sp = return_sp;
           handler_fp = frame->fp();
+
+          // This is going to be handled by Wasm, so we need to set the TLS flag
+          // again.
+          if (trap_handler::UseTrapHandler()) {

[titzer, 2017/03/01 16:48:47]

Any harm in moving the if inside the SetThreadInWasm?

[Eric Holk, 2017/03/01 17:26:13]

Nope, in fact it's already there. I'll remove it here.

Done.

+            trap_handler::SetThreadInWasm();
+          }
+
           break;
         }
       }